Recovery of chlorine from gas mixtures



Patented Feb; 28, 1933,

UNITED STATES BRUNO UEBLER, OF BERLIN, GERMANY RECOVERY OF CHLORINE FROM G AS MIXTURES nanrawin Original application filed June 17, 1929, Serial no. 371,707, and in Germany September 17, 1927. Divided and this application filed October 17, 1930. Serial No. 487,023.

This applicationis a division-of U. s. patent application Ser."No.'371,707, filedJune 17,1929, and hasbeen filed in Germany, September 17 1927. 1

5 My invention refers to the production of nitrates and has for its particularobjectto produce nitrates from chlorides. and nitric acid or nitrous gases without losing any nitrogen. I

the starting material must be readily available and therefore nitrous gases or nitric acid on the one hand and metal chlorides, more especially potassium chloride, on the other hand are used for this purpose; All the proc esses hitherto devised, however, donot pay suflicient attention to the losses of nitrogen arising in the reactions. In order to exclude any such losses, the reaction I KC1+HNO3=KNO +HGI (I) must take place quantitatively in such manner that all the chlorine escapes in the form of hydrochloric acid or that according to the reaction all the chlorine escapes as such, without any nitrogen oxide being lost. I

In reality, however, the reaction II as'a rule occurs differently, viz;

I then obtain a mixture of N0 and G1, which I can be separated by liquefaction in the, cold and fractional distillation, the chlorine escaping first,

In the production of nitrates on a big scale Example 1 I The gas mixture obtained by actingwith nitric acid on potassium chloride, such mix-u,

ture consisting of 9.5% nitrosyl chloride,

17.5% chlorine and 73% nitrogen, is cooled down to CL, in order to altogether remove the nitrosyl chloride from the inert.

gases. There separates out a liquid mixture composed of approximately equal parts of nitrosyl chloride and chlorine. The inert gases, which escape, are washed with small quantities of water, in order to remove the .last traces of nitrosyl chloride and can moreover be conducted with great success over ferric chloride. is subjected to fractional distillation at about 30 C; In the distillation almost exclusively chlorine escapes, containing only a low percentage of NOGl. This latter is quantitatively'removed when the gases are coni ducted over ferric chloride.

Various changes may be made in the de- I tails disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof.

Throughout the specification and the claim aflixed thereto the expressions liquefaction, liquefied gas and liquid gas are intended to refer to the production of the gas as such in the liquid phase, as distinguished from mere solutions of the gas or compounds there- The liquefied gas mixture [PATENT OFFICE, 7

of in ordinary solvents, such as waterand the like.

I claim In the process of producing alkali nitrates from alkali'chlorides and nitric acid or nitrous' gases the steps which comprise separating from the mixture of chlorine and nitrosyl i chloride formed in the reaction of the major quantity of the free chlorine by thermic decomposition and quick cooling down of the mixture, through which air is passed, until complete liquefaction of N02 and ()1 has taken place, and subjecting the liquefied gas to fractional distillation.

In testimony whereof I aflix my signature.

BRUNO UEBLER.- 

